class Dog:
    # 一次模拟小狗的简单尝试
    def __init__(self, name, age):
        # 初始化name和age
        self.name = name
        self.age = age
    def sit(self):
        # 模拟小狗收到命令坐下
        print(f"{self.name} is now sitting")
    def roll_over(self):
        # 模拟小狗收到命令打滚
        print(f"{self.name} is now rolling over")
my_dog = Dog('Jack', 20)
your_dog = Dog('John', 10)
print(f"My dog's name is {my_dog.name} and my age is {my_dog.age}")
my_dog.sit()
print(f"\nYour dog's name is {my_dog.name} and my age is {my_dog.age}")
your_dog.sit()